Well, this all depends on what college or even what type of college she's hoping to get into. A 3.4 and a 23 are good enough for the vast majority of schools, but schools like those in the Ivy League are going to have higher standards. Converting my actual average to a GPA on a 4.0 scale gives me the same as you, a 3.4 and I got a 1950 (including a 710 writing which most schools don't look at) on my SATs as well as several SAT II scores above 600. I also scored a 3 on the APUSH exam. I play two sports and I'm an anti-bullying counselor at my school. Yet Princeton and Carleton (not an Ivy, but still a hard school to get into) rejected me. The two kids I know who got into Ivies have 3.9/4.0 GPAs scored a 2110 and a 2250 respectively on the SATs.
True, most schools (including most state schools) will take you with a 3.4 and a good test score (be it the ACT or the SAT), but there are those that want higher scores and averages.
That being said, I wound up at a state school. GO UNH WILDCATS!